| FASTENER LENGTH | 0.438 INCHES NOMINAL |
| HEAD HEIGHT | 0.172 INCHES MINIMUM AND 0.190 INCHES MAXIMUM |
| HEAD STYLE | HEXAGON |
| MATERIAL DOCUMENT AND CLASSIFICATION | QQ-S-633 FED SPEC ALL MATERIAL RESPONSES OVERALL |
| MATERIAL | STEEL COMP 1010 OR STEEL COMP 1020 OVERALL |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| PRIMARY WASHER OUTSIDE DIAMETER | 0.466 INCHES MINIMUM AND 0.478 INCHES MAXIMUM |
| PRIMARY WASHER STYLE | FLAT INTERNAL TEETH |
| PRIMARY WASHER MATERIAL THICKNESS | 0.025 INCHES NOMINAL |
| WASHER QUANTITY | 1 |
| WIDTH BETWEEN FLATS | 0.428 INCHES MINIMUM AND 0.438 INCHES MAXIMUM |
| SURFACE TREATMENT | CADMIUM OR ZINC OVERALL |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.438 INCHES MAXIMUM |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) |
| THREAD QUANTITY PER INCH | 20 |